South Asians living in the United States are at much higher risk for type 2 diabetes than are whites and immigrants from other Asian countries, a new small study reveals.

The study classified Asians born in Bangladesh, India, Nepal and Pakistan as South Asians. The other Asian subgroup consisted of those born in China, the Philippines, North and South Korea, Thailand, Vietnam and other nations.

Researchers used data from the New York City Health and Nutrition Examination Survey, conducted in 2004, to evaluate different racial and ethnic groups for risk factors relating to heart disease and metabolic disorders such as diabetes.

Their findings, based on fasting glucose levels from 1,324 respondents, appears in the latest issue of the journal Ethnicity & Disease.

“In addition to cultural and lifestyle factors, Asians subgroups are also different in terms of their genetic makeup,” said lead study author, Swapnil Rajpathak, M.D., an assistant professor of epidemiology and population health at the Albert Einstein College of Medicine.

These variations contribute to the disparity in diabetes risk between whites and Asians overall, as well as between South Asians and Asians from other countries.

As many as 1 million Asian-Americans live in New York City, accounting for 10 percent of its total population, and this number is projected to increase.

After adjusting for age, the researchers found that South Asians had the highest prevalence of diabetes at 35.4 percent, compared with 16.1 percent for all Asians and 10.8 percent for whites.

Although these figures rely on a small sample size, the research demonstrates a need for more studies focusing particularly on the elevated risk among South Asians, said Rajpathak, who emigrated from India.

“Immigrants may experience dramatic changes in their diet and physical activity after moving to this country,” he said. “Given their higher genetic susceptibility, unfavorable changes in lifestyle factors may increase the risk of diabetes.”

The findings are of “great interest” but come as “no surprise,” said Vivian Fonseca, M.D., vice president of the American Diabetes Association and chief of endocrinology at Tulane University Health Sciences Center.

In general, “Asians get insulin resistance and increased risk of diabetes and heart disease at a much lower level of obesity than Caucasians,” he said.

To address the disparity, the American Diabetes Association is planning awareness programs aimed specifically at South Asians. Fonseca said the educational efforts “need to be culturally sensitive, understandable for people who may not be fluent in English.”

Rajpathak SN, et al. Elevated risk of type 2 diabetes and metabolic syndrome among Asians and South Asians: results from the 2004 New York City HANES.